Localizations according to flask.ext.babel standard mechanism
locales validation and remove duplication of en_US in settings
Check for default language corruption
commented code deleted
Explicit Babel defaults removed
Make fixed format Fortran work in sagenb
Merge pull request #237 from migeruhito/localization

Localization procedure fixes/checks  and other minor bugs
Merge pull request #290 from kcrisman/fortran

Make fixed format Fortran work in sagenb